This invention generally relates to an assembly for supporting an end of a load bearing member in an elevator system.
Elevator systems typically include a cab that moves between landings in a building, for example, to transport passengers or cargo between the various floors or levels in the building. Many elevator systems include a counterweight that moves as the cab moves. A variety of driving mechanisms are known for causing the desired movement of the cab and counterweight.
Often a load bearing member couples the cab to the counterweight. The load bearing member typically is referred to as roping or a belt depending on the configuration. The load bearing member rides over sheaves as the cab moves between the various landings.
One challenge facing elevator system designers is how to adequately secure and support the ends of the load bearing member. Conventional techniques include using a socket and wedge termination assembly that clamps an end of the load bearing member between a socket and a wedge. A pivoting dead-end hitch typically is provided to accommodate necessary angular movement of the termination assembly during elevator system operation. In many situations, multiple load bearing members (i.e., multiple belts) are used and a spring support is necessary to accommodate varying loads on the different load bearing members at any given moment, for example.
Conventional arrangements are not without drawbacks and shortcomings. One drawback of the conventional socket and wedge termination assemblies is the cost associated with manufacturing such assemblies. The socket, for example, is typically made using a casting process, which tends to be expensive. Moreover, accommodating the appropriate tolerance levels required for secure arrangements introduces additional complexity and cost into the manufacturing process. Another shortcoming of conventional arrangements is that they take up valuable space within the packaging constraints of the elevator system. The amount of vertical space typically required for conventional arrangements is often considered to be too much.
There is a need for an improved belt termination assembly that is more economical and requires less space than conventional arrangements. This invention addresses that need while avoiding the shortcomings and drawbacks associated with prior designs.
In general terms, this invention is an assembly for supporting an end of a load bearing member, such as a belt, in an elevator system.
An assembly designed according to this invention includes a first support member that has at least one stop portion. The first support member is adapted to be rigidly positioned in a suitable location within the elevator system.
A second support member is received relative to the first support member. The second support member supports a portion of the load bearing member. There preferably is at least one stop portion on the second support member.
A plurality of motion limiters cooperate with the stop portions to limit relative motion between the first and second support members. In one example, the motion limiters are made using a polyurethane material.
One example embodiment of the inventive assembly includes cover members at opposite longitudinal ends of the second support member. The cover members maintain the motion limiters between the first and second support members. The cover members also preferably extend radially far enough to provide shoulder surfaces to assist in aligning a load bearing member on the second support member.
In situations where a plurality of second support members are provided to accommodate a plurality of load bearing members, spacers preferably are positioned between the covers of adjacent second support members to maintain a desired axial spacing between them and to allow the individual second support members to move relative to a corresponding first support member independent of the other second support members.
The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiment. The drawings that accompany the detailed description can be briefly described as follows.